Polycyclic aromatic hydrocarbon-degrading bacteria in Anacostia River sediments: Presence and metabolic capabilities

Polycyclic Aromatic Hydrocarbons (PAHs) are universal, harmful, environmental contaminants capable of polluting soils and sediments for long periods of time, particularly in urban systems such as the Anacostia River. Many species of bacteria have been shown to degrade PAHs by using them as an energy source. Twenty-one strains representing three different regions (upstream, middle and downstream) of the Anacostia River system were capable of degrading either the PAHs or bezene, toluene and xylene (BTX) compounds, with many strains able to utilize multiple PAHs as the carbon source. Microbial community analysis using the WST-1 respiration indicator showed potential for utilization of all tested PAHs, with variation seen between sampling sites. PCR of the PAH-degrading gene familes tmoA, NDO, and nidA, showed a genetic capacity for PAH degradation at all sampling sites. DGGE revealed four types of tmoA genes, five types of NDO, and eight types of nidA-like genes in the Anacostia system. The presence of each type of gene differed between and within sampling sites, suggesting diverse potential for PAH-degradation in these soils.</p

1179. Septic shock in <i>Coccidioides immitis</i> Infection

Abstract Background Coccidiodes can cause severe or disseminated disease in a minority of patients, but coccidioidomycosis resulting in septic shock is rare. We describe a case of fulminant C. immitis infection whose diagnosis was delayed by a markedly elevated serum procalcitonin. We review the published literature of coccidioidomycosis complicated by septic shock. Case Report A 74-year-old man presented with cough, fever, and three weeks of progressive decline. He was febrile at 39.1°C, tachycardic, and tachypneic with crackles in the left lung; an initial procalcitonin (PCT) was 1.73 ng/mL. Broad-spectrum antibacterials were administered. His condition worsened on the 2nd day, requiring vasopressors, endotracheal intubation, and hemodialysis. PCT rose to &amp;gt; 400 ng/mL. Respiratory cultures grew fungi consistent with Coccidioides. Liposomal amphotericin B (AmB) was initiated. His shock progressed, and he died on hospital day 6. Methods We performed a MEDLINE and Google Scholar search using the terms “coccidioidomycosis”, “Coccidioides”, “sepsis”, and “septic shock”. Indexed articles and conference abstracts were included if the patient had confirmed coccidioidomycosis and vasopressor-dependent shock with no alternate cause. Data on age, sex, ethnicity, comorbidities, antifungal therapy, and outcome were tabulated. Results We identified 18 reports describing 31 patients with vasopressor-dependent septic shock due to Coccidioides since 1993 (table 1). Of these cases, 23/31 (74.2%) died. Of those with reported race/ethnicity, 20/23 were Latino, 4/23 of African descent, 5/23 Asian-Pacific Islander, and 3/23 white. 27/31 (87.1%) were male. All but two were adults (median age 51.5 years). 21/31 (67.7%) had reported comorbid conditions. 20/31 patients (64.5%) and all of the survivors received AmB-based therapy. Table 1 - Published cases of coccidioidomycosis complicated by septic shock. All ages are in years. Abbreviations: HIV/AIDS = human immunodeficiency virus/acquired immunodeficiency syndrome; CAD = coronary artery disease; COPD = chronic obstructive pulmonary disease; ESRD = End stage renal disease; SLE = Systemic Lupus Erythematosus; APC = recombinant human activated protein C (drotrecogin alfa). Conclusion Coccidioidomycosis is an elusive diagnosis in critically-ill patients due to its rarity, the lack of rapid diagnostics, and its propensity to mimic other infections. Mortality is high, potentially due to delays in diagnosis. The marked elevation in PCT has not been previously noted in coccidioidomycosis and may further confound diagnosis. Improved diagnostics and the rapid institution of AmB may reduce mortality in patients with coccidioidal sepsis. Disclosures All Authors: No reported disclosures </jats:sec

1014. Factors Associated with Switching from Tenofovir Diproxil Phosphate to a Tenofovir Alafenamide Based Regimen in a Cohort with Unrestricted Access to Care and Medications

Abstract Background Background- Tenofovir alafenamide (TAF) is associated with fewer renal and bone toxicities than tenofovir disoproxil phosphate (TDF). Hence, most experts suggest switching to TAF. We examined factors associated with switching to TAF in the US Military HIV Natural History Study (NHS), a cohort of people living with HIV who have unrestricted access to care and medications. Methods Methods- The first formulation of TAF received FDA approval on 1 November 2015; hence, we included all NHS participants with visits between November 2015 and March 2019. Patient factors including race, gender, CD4 count, antiretroviral therapies (ART), viral load, HIV diagnosis era, presence of comorbidities (cancer, heart disease, dyslipidemia, kidney disease and obesity), were assessed for association with a switch to TAF with a logistic regression model. Results Results- Of the 1678 eligible participants, 1324 (63%) had received a TDF-based regimen. Participants who received a TDF-regimen were 94% male 44% African-American [AA], 39% Caucasians and 17% Hispanic. About half the participants who received TDF-based ART switched to a TAF-based regimen (n=682, 52%). Of the 425 (32%) participants receiving TDF/FTC co-formulated with efavirenz, 48% (n=206) switched to TAF. The proportions switching to TAF were higher in those receiving TDF/FTC co-formulated with rilpivirine [59%, n=90] or elvitegravir/cobicistat [68%, n=146]. The common ART regimens after the switch were: TAF co-formulated with elvitegravir/cobicistat (46%), rilpivirine (16%) or bictegravir (12%) and TAF/FTC combined with dolutegravir (15%). In an adjusted analysis, older participants, and participants receiving TDF/FTC in combination with efavirenz, dolutegravir, raltegravir, boosted protease inhibitors or a combination of boosted protease inhibitors and integrase inhibitors (other) were less likely to switch, table 1. Conclusion Conclusions- Despite the unrestricted access to care and ART in the NHS, only half of the participants switched to TAF. Participants on efavirenz-containing regimens were less likely to switch to a TAF-based regimen, possibly due to the lack of a co-formulated single tablet. These trends need to be followed and barriers to switching to TAF (both patient and provider) need examination. Table 1- Factors associated with switching to a Tenofovir Alafenamide Based Regimen Disclosures All Authors: No reported disclosures </jats:sec

Natural History of Aerosol Exposure with Marburg Virus in Rhesus Macaques

Marburg virus causes severe and often lethal viral disease in humans, and there are currently no Food and Drug Administration (FDA) approved medical countermeasures. The sporadic occurrence of Marburg outbreaks does not allow for evaluation of countermeasures in humans, so therapeutic and vaccine candidates can only be approved through the FDA animal rule—a mechanism requiring well-characterized animal models in which efficacy would be evaluated. Here, we describe a natural history study where rhesus macaques were surgically implanted with telemetry devices and central venous catheters prior to aerosol exposure with Marburg-Angola virus, enabling continuous physiologic monitoring and blood sampling without anesthesia. After a three to four day incubation period, all animals developed fever, viremia, and lymphopenia before developing tachycardia, tachypnea, elevated liver enzymes, decreased liver function, azotemia, elevated D-dimer levels and elevated pro-inflammatory cytokines suggesting a systemic inflammatory response with organ failure. The final, terminal period began with the onset of sustained hypotension, dehydration progressed with signs of major organ hypoperfusion (hyperlactatemia, acute kidney injury, hypothermia), and ended with euthanasia or death. The most significant pathologic findings were marked infection of the respiratory lymphoid tissue with destruction of the tracheobronchial and mediastinal lymph nodes, and severe diffuse infection in the liver, and splenitis

Adjusted hazard ratio (HR) of incident sexually transmitted infections (STIs) by site and type of STI and use of HIV pre-exposure prophylaxis (PrEP) medication (TDF/FTC).

Adjusted hazard ratio (HR) of incident sexually transmitted infections (STIs) by site and type of STI and use of HIV pre-exposure prophylaxis (PrEP) medication (TDF/FTC).</p